![[Picture of a GBA with arrows on it]](gameboy.png)
I, Damian Yerrick, am developing a rhythm video game for the Game Boy Advance handheld game system.
I, Damian Yerrick, am developing a rhythm video game for the Game Boy Advance handheld game system.
2004 March 14: It has come to my attention that popular GBA emulators' latency may make them unsuitable for use with rhythm games.
2004 February 29: I've settled on Good audio for this project. I'm now looking for 1. suggestions of royalty-free music to use, and 2. comments on the graphical style of the screenshots.
Because the GBA's processor cannot decode an MP3 bitstream in real time, I have to use some other method to compress audio. I have several codecs in mind; all introduce some noise into the sound. There's a tradeoff: the noisier the codec, the more songs you can squeeze onto a 256 Mbit flash cartridge.
Previously, I asked people to compare files that have been round-tripped through three different codecs. Based on the response I got, I've settled on Good. For historical purposes, here are the samples, at 1.6 MB each:
Decoding Good in real time takes about 50 percent of CPU time. Here's a GBA demo (356 KB) that decodes Good in real time. (Great and Perfect are much simpler codecs and will take much less CPU time to decode.) Here's some encoder and decoder source code under a permissive license.
The game should look somewhat like this mock-up. I will warn you that the engine is still in planning stages; nothing is implemented but an audio codec.
Your favorite GBA emulator may not be suitable for use with rhythm games. Many of them add an unacceptable amount of latency between controller state changes and the corresponding audio output, resulting in missed steps. You can test this with a ROM of Dance Dance Revolution GB, or if you don't want to pirate anything, you can test this with my GBA delay tester (3 KB).
If you write dance music, and you're willing to let me redistribute your songs and recordings without royalty in a non-commercial tech demo, please contact me.
Please feel free to comment on anything on this page through the private messaging system of gbadev, ddrei, or bemanistyle forums (my nick on all three sites is tepples) or through this webmail form.
Return to Pin Eight: GBA
Copyright 2004 Damian Yerrick. Verbatim reproduction and distribution of this page are permitted. Nintendo and Game Boy are trademarks of Nintendo. Dance Dance Revolution is a trademark of Konami.